Was looking around for a low-voltage headamp circuit I could build, which I could power with the USB battery pack I already carry around (an XtremeMac InCharge Portable) when I came across this TDA1308 circuit :

Was looking around for a low-voltage headamp circuit I could build, which I could power with the USB battery pack I already carry around (an XtremeMac InCharge Portable) when I came across this TDA1308 circuit :

Would it not be easier just to implement the circuit on the datasheet? It is single supply already....

I've built a TDA1308 amp based on the circuit proposed in the datasheet, sounds great with my KRK KNS8400 phones @ 32 ohms impedance, however it certainly doesn't have the juice to power my 600 ohm Beyer DT880s. Did you try playing around with the gain resistors?

Any suggestions as to how I can customise the gain resistors for DT800 (600 ohm)?